Back-rest with adjustable lordosis support for seats

ABSTRACT

A back rest for a seat wherein the back rest includes a support member having first and second edge surfaces, a central plate between the edge surfaces, a first side member coupling the central plate to the first edge surface, and a second side member coupling the central plate to the second edge surface. The central plate of the support member is recessed from the first and second end surfaces to define a cavity. The back rest further includes a plurality of protrusions extending from the central plate and into the cavity. Additionally, the back rest includes a lordosis support having first and second ends coupled to the plurality of protrusions, at least one of the first and second lordosis support ends being coupled to the plurality of protrusions for movement relative to the support member. The lordosis support is adapted to bow upon displacement of one of the first end and the second end thereof toward one another thereby forming a curvature. In another embodiment a back rest includes a support member defining an opening and a separately formed bulge member defining side surfaces and a central plate recessed from and integral with the side surfaces to define a cavity. The back rest according to this embodiment also includes connectors for coupling the bulge member to the support member.

The invention concerns a back-rest for seats of all kinds, especiallyfor car seats, office chairs and armchairs, with an essentially flatsupport piece and an adjustable lordosis support, where the flat supportpiece is constructed, at least in the area where the lordosis support islocated, as a tub-like bulge, which contains protrusions as holdingdevices and/or guides for attaching and guiding the lordosis support.

From the EP-A1-0 011 396, the U.S. Pat. No. 4,182,533 and the DE-A-23 46125, back-rests for seats in accordance with the characterizing portionof claim 1 are known.

In these cases, the flat support piece is always of a large size andthus it is difficult to handle during the mounting of the adjustablelordosis support.

It is the objective of the invention to construct the back-rest of aseat with a flat support piece and with an adjustable lordosis supportin such a manner that the production and mounting are simplified.

This objective is being achieved by a back-rest having thecharacteristics of claim 1.

Information concerning advantageous embodiments of the invention can begathered from the subordinate claims.

The invention will be explained below in more detail on the basis ofdifferent examples of its embodiments and by reference to the drawings.The following is shown:

FIG 1 a support piece for a back-rest in the form of a channel, which isdisposed at a frame and contains a lordosis support, which can beadjusted with regard to its height and its curvature;

FIG. 2 the same as in FIG. 1 in a longitudinal section;

FIG. 3 the same as in FIG. 1 in a transverse section;

FIG. 4 a support piece for a back-rest, which has been integrated into abowl with a bulge;

FIG. 5 the same as in FIG. 3 in a longitudinal section;

FIG. 6 the same as in FIG. 3 in a transverse section;

FIG. 7 a support piece for a back-rest with a recess, in which aseparate formed part with a bulge has been disposed;

FIG. 8 a section along line VIII--VIII in FIG. 7;

FIG. 9 a section along line IX--IX in FIG. 7;

In FIGS. 7 to 9, examples of an embodiment in accordance with the claimsare shown, whereas the example of the embodiment shown in FIGS. 1 to 6only show individual characteristics of the claims.

The example of the embodiment of a back-rest shown in FIGS. 1 to 3includes a support piece 1 in the shape of a channel 1a with a centralplate 2 and with side pieces 3, which are disposed at an angle to it,while their free edges 4, which are at an angle, are supported on thelateral bars of a frame 5 of a back-rest.

The support piece 1 consists of an essentially rigid material, forexample of a plastic material, while the frame 5 consists preferably ofa metal and can be constructed in a U-shaped form. The support piece 1is additionally attached to the cross-struts 6 and 7--preferably made ofmetal--of the frame 5 by means of fastening elements 8, which aredisposed at the rear side of the support piece 1. In the example of theembodiment, the cross-struts 6, 7 have a circular cross-section, and thefastening elements 8 (FIG. 2 and 3) on the rear side of the supportpiece 1 are constructed as snap connections for receiving thecross-struts 6, 7. By means of this type of snap connection, the supportpiece 1 can be attached to the frame 5 in a simple and rapid mannerwithout the use of a tool.

In the central plate 2, two guides 9 are provided, both at the top andat the bottom, on which guides the upper and the lower end of thelordosis support 10 are positioned in such a manner that they are bothmovable. The guides 9 are preferably made in such a way that thelordosis support 10 can be inserted in them or placed upon them withouta tool, preferably in the form of any type of known slide and/or snapconnections. The guides 9 can, for example, be made as protruding railsor in the form of recesses, and they have the purpose of placing theends of the lordosis supports 10 in or upon them in such a manner thatthey are movable.

In the central plate 2, two guides 9 are provided, both at the top andat the bottom, on which guides the upper and the lower end of thelordosis support 10 are positioned in such a manner that they are bothmovable. The guides 9 are preferably made in such a way that thelordosis supports 10 can be inserted in them or placed upon them withouta tool, preferably in the form of any type of known slide and/or snapconnections. The guides 9 can, for example, be made as protruding railsor in the form of recesses, and they have the purpose placing the endsof the lordosis supports 10 in or upon them in such a manner that theyare movable.

The plate 2 further contains two deflection elements 11 and 11'. Aroundthe deflection elements 11 or 11', respectively, cable pulls 12 or 12'respectively, which are deflected by approximately 90°, are guidedtoward adjustment devices 13 or 13', respectively, by means of controlknobs 14, 14' along the frame 5. The other ends of the cable pulls 12,12' are fastened to the upper ends or the lower ends, respectively, ofthe lordosis support 10.

In the example of the embodiment, a tension spring 15 is secured to theupper end of the lordosis support 10, which tension spring is attachedto a holding device 16 at its other end. By turning the control knob 14of the adjustment device 13 with the assistance of the tension spring15, the cable pull 12 is elongated or shortened, respectively, whichmakes it possible to adjust the height of the lordosis support 10. Byturning the control knob 14' of the adjustment device 13', the cablepull 12' can be shortened or elongated, respectively, which makes itpossible to cause the elastic lordosis support 10 to be curved more orto be relaxed, i.e. to become flatter. By the use of the deflectionelements 11, 11' the need for a Bowden control shell for the adjustmentof the lordosis support 10 no longer exists, which reduces theproduction costs, because now merely a cable pull 12, 12' will be neededfor each adjustment device 13, 13'; finally, the assembly will also bemade easier by the simple placement of the cable pull, which issuspended free of tension, upon the deflecting elements 11, 11'.

Instead of the two guides 9, two holding devices (not shown) can beprovided on the top and the bottom of the plate 2 in order to provide afixed receiving means for one end of the lordosis support 10. In thiscase, the lordosis support 10 would only be able to be given an outwardcurvature, but its height would not be adjustable.

Preferably, the plate 2 along with the fastening elements 8 and theguides 9, and possibly also including the holding devices, and undercertain circumstances even including the deflection elements (11, 11'),would be produced in one piece from plastic in an injection moldingprocess, which would reduce the production costs to a minimum. In orderto ensure a wide range of adaptability to differently shapedcross-struts 6, 7 and to facilitate their disposal at various distances,the fastening elements 8 can be, in accordance with a version not shown,made separately and can be inserted into horizontal and/or verticalslots in the plate 2 (not shown).

In the case of the example of the configuration of a back-rest shown inFIGS. 4 to 6, which is known in particular from the example of officechairs, the flat support piece 1 is made in the shape of a bowl 17. Thebowl 17 includes a tub-like bulge 18, which has the form of anapproximately rectangular recess for receiving a lordosis support, whichis not shown. In the bulge 18 protrusions 19 are provided, whichfunction as holding devices and/or guides for the attachment and theguidance of a lordosis support, as has been shown in the description ofFIGS. 1 to 3.

In the bulge 16, a deflection element 11 can be provided, or there canalso be two deflection elements 11, which then would be disposed asmirror images of each other, and which can serve the purpose ofdeflecting one or two cable pulls, which are attached to the upperand/or the lower end of the lordosis support. This embodiment of thesupport piece 1 is preferably made of a plastic material in one piece,and it includes a through hole 20 for the cable pull leading to anadjustment device (not shown), which through hole is located at one or,if necessary, at both sides of the lateral boundary of the recessedbulge 18. The bowl 17 may contain elements 21 at its rear side, whichare not described in detail, which elements have the purpose ofattaching the back-rest to a seat.

In the example of an embodiment shown in FIG. 7, the flat support piece1 can have any contour or even spatial shape at all, which is adapted tothe particular purpose of use. In the area where the lordosis support isto be placed (not shown), the support piece 1 contains an open recess22. Above the recess 22, a separate formed piece 23 can be disposed,which has a tub-like bulge 24 with a flange-like edge 25. The formedpiece 23 includes the guides and the holding devices as well as thedeflection elements, as they have been described in the embodiments,that were discussed earlier. It has been made or adapted for thereception of an adjustable lordosis support. The formed part 23 with itsedge 25 can be attached in such a manner above the recess 22, that iteither completely or partly covers it, and in this manner it (the formedpart) facilitates the attachment above or below the support piece 1.

The attachment of the formed part 23 to the support piece 1 can beachieved in several different ways. According to FIG. 8, the supportpiece 1 as well as the edge 25 of the formed part 23 contain drilledholes 26, which can be brought into alignment with one another, andwhere the drilled holes 26 of one of the parts can be made as elongatedholes in order to make the assembly easier, in which case the drilledholes are then disposed in such a manner that they are displacedrelative from each other by 90°. By means of these drilled holes 26, thesupport piece 1 can be connected to the formed part 23 in a permanentand fixed manner or detachably, for example, by means of rivets 27 or byscrew connections. If the formed part 23 is attached to the supportpiece 1 (see FIG. 9), in which case its bulge 24 extends through therecess 22, protrusions 28 can be added to the support piece 1 in such amanner that their location corresponds to that of the round holes oreven the elongated holes 29 in the edge 25 of the formed part 23. Theseprotrusions 28 can contain an expandable head 30, for example with aslot 31, which can be diverted during their introduction through a holeor an elongated hole 29, and which then once again expands in the endposition--thus seeing to it that the formed part 23 is locked to thesupport piece 1. This embodiment constitutes a simple design and theprotrusions 28 with the expandable heads 30 as well as the holes 29 canbe manufactured, along with the individual parts required, without anyadditional steps by means of the injection molding process and with theuse of plastic materials. The protrusions 28 can, of course, also belocated in the formed part 23, and the holes 29 in the support piece 1.The heads 30 of the protrusions can also be molded in place as a meansof connecting the two parts. It is also possible to attach the supportpiece 1 to the formed part 23 by means of any kind of adhesive, locking,snap or coupling connection.

The bulges are preferably of a rectilinear configuration, because theyhave the purpose of receiving the lordosis supports, which in most caseshave matching dimensions. For reasons of manufacturing technology, thelateral edges of the bulges can be tapered and the corners rounded. Forreasons of appearance, the bulges can also have different contours, forexample they can be round, oval or polygonal.

The support pieces, in any configuration, are preferably made of plasticby means of an injection molding or a forming process, which can alsoinclude the use of reinforcement inserts. However, the use of anymaterial at all is possible, for example one that can be formed or acomposite material may be used.

We claim:
 1. A back rest for a seat, said back rest comprising:a supportmember including an edge surface and a central plate recessed from saidedge surface to define a cavity; protrusions coupled to said centralplate; a lordosis support having first and second ends coupled to saidprotrusions for movement relative to said support member, said lordosissupport adapted to bow upon displacement of one of said first and secondends toward the other of said first and second ends thereby forming acurvature; and actuator means coupled to said lordosis support, saidactuator means including a vertical adjustor for selectively verticallymoving said first and second ends of said lordosis support relative tosaid support member and an arching adjustor for changing the curvatureof said lordosis support.
 2. The back rest of claim 1 wherein each ofsaid protrusions guide the vertical movement of said lordosis supportrelative to said support member.
 3. The back rest of claim 1 whereinsaid arching adjustor includes a first cable and a first controllercoupled to said support member for movement relative thereto, said firstcable coupled to said first controller, extending into said cavity, andcoupled to said lordosis support.
 4. The back rest of claim 3 whereinsaid arching adjustor further includes a deflection element disposed insaid cavity and coupled to said support member, said first cableoperationally coupled to said deflection element such that saiddeflection element deflects said first cable between said firstcontroller and said lordosis support.
 5. The back rest of claim 3wherein said lordosis support further includes aide memberinterconnecting said edge surface and said central plate, said sidemember defines an opening and said first cable extends from said firstcontroller through said opening and into said cavity.
 6. The back restof claim 3 wherein said vertical adjustor includes a second cable and asecond controller coupled to said support member for movement relativethereto, said second cable coupled to said second controller, extendinginto said cavity, and coupled to said lordosis support.
 7. The back restof claim 6 wherein said lordosis support further includes a side memberinterconnecting said edge surface and said central plate, wherein saidside member defines a hole and said second cable extends from saidsecond controller, through said hole and into said cavity.
 8. The backrest of claim 6 wherein said vertical adjustor further includes adeflection element disposed in said cavity and coupled to said supportmember, said second cable operationally coupled to said deflectionelement such that said deflection element deflects said second cablebetween said second controller and said lordosis support.
 9. A back restfor a seat, said back rest comprising:a support member including firstand second edge surfaces, a central plate, a first side member couplingsaid central plate to said first edge surface, and a second side membercoupling said central plate to said second edge surface, said first edgesurface extending outwardly from said first side member and away fromsaid central plate, said second edge surface extending outwardly fromsaid second side member and away from said central plate, said centralplate being recessed from said first and second edge surfaces to definea cavity; and a plurality of protrusions extending from said centralplate and into said cavity for coupling a lordosis support to saidsupport member.
 10. The back rest of claim 9 further including alordosis support having first and second ends coupled to said pluralityof protrusions, at least one of said first and second lordosis supportends being coupled to said plurality of protrusions for movementrelative to said support member, said lordosis support adapted to bowupon displacement of one of said first end and said second end thereoftoward one another thereby forming a curvature.
 11. The back rest ofclaim 10 further including arching adjustor means coupled to saidlordosis support for adjusting the curvature of said lordosis support,said arching adjustor means includes a first cable and a firstcontroller coupled to said support member for movement relative thereto,said first cable coupled to said first controller, extending into saidcavity, and coupled to said lordosis support.
 12. The back rest of claim11 wherein said arching adjustor means further includes a deflectionelement disposed in said cavity and coupled to said support member, saidfirst cable operationally coupled to said deflection element such thatsaid deflection element deflects said first cable between said firstcontroller and said lordosis support.
 13. The back rest of claim 11wherein said first side member defines an opening and said first cableextends from said first controller through said opening and into saidcavity.
 14. The back rest of claim 10 wherein each of said first andsecond ends of said lordosis support are coupled to said protrusions forvertical movement relative to said support member.
 15. The back rest ofclaim 14 further including vertical adjustor means coupled to saidlordosis support for vertically moving said first and second lordosissupport ends relative to said support member, said vertical adjustormeans includes a second cable and a second controller coupled to saidsupport member for movement relative thereto, said second cable coupledto said second controller, extending into said cavity, and coupled tosaid lordosis support.
 16. The back rest of claim 15 wherein said secondside member defines a hole and said second cable extends from saidsecond controller, through said hole and into said cavity.
 17. The backrest of claim 15 wherein said vertical adjustor means further includes adeflection element disposed in said cavity and coupled to said supportmember, said second cable operationally coupled to said deflectionelement such that said deflection element deflects said second cablebetween said second controller and said lordosis support.
 18. The backrest of claim 15 wherein each of said plurality of protrusions guidesthe vertical movement of said lordosis support relative to said supportmember.
 19. The back rest of claim 15 wherein at least one of saidplurality of protrusions guides the movement of one of the first andsecond ends of said lordosis support.
 20. The back rest of claim 10wherein one of said first and second ends of said lordosis support isfixedly coupled to it least one of said plurality of protrusions. 21.The back rest of claim 10 wherein at least one of said plurality ofprotrusions is a rail and said lordosis support is coupled to saidsupport member by sliding engagement with said rail.
 22. The back restof claim 10 wherein said central plate includes recesses defining saidprotrusions and wherein said lordosis support is coupled to said supportmember in a snap-fit engagement with said recesses.
 23. The back rest ofclaim 9 wherein said central plate is integral with said first andsecond side members, said first and second side members being integralwith said first and second edge surfaces.
 24. The back rest of claim 9wherein said protrusions are integral with said central plate.
 25. Theback rest of claim 9 herein said support member further includes anupper end and a lower end and said cavity extends between said upper endand said lower end to define a channel therebetween.
 26. The back restof claim 9 further including a frame and coupling means for connectingsaid support member to said frame.
 27. The back rest of claim 26 whereinsaid coupling means includes a connector element coupled to said frame,and a fastening element coupled to said support member, said fasteningelement adapted to receive said connector element in a snap-fitengagement to connect said support member to said frame.
 28. A back restfor a seat, said back rest comprising:a support member defining anopening; a separately formed bulge member having side surfaces and acentral plate recessed from and integral with said side surfaces todefine a cavity; connecting means for coupling said bulge member to saidsupport member; and a lordosis support and a plurality of protrusionsextending from said central plate and into said cavity, said lordosissupport including first and second ends coupled to said plurality ofprotrusions, at least one of said first and second lordosis support endsbeing coupled to said plurality of protrusions for movement relative tosaid support member, said lordosis support adapted to bow upondisplacement of one of said first and said second ends thereof towardone another thereby forming a curvature.
 29. The back rest of claim 28,further including arching adjustor means coupled to said lordosissupport for adjusting the curvature of said lordosis support, saidarching adjustor means includes a first cable and a first controller,said first cable coupled to said first controller, extending into saidcavity, and coupled to said lordosis support.
 30. The back rest of claim29, wherein said arching adjustor means further includes a deflectionelement disposed in said cavity and coupled to said support member, saidfirst cable operationally coupled to said deflection element such thatsaid deflection element deflects said first cable between said firstcontroller and said lordosis support.
 31. The backrest of claim 30,further including vertical adjustor means including a second cable and asecond controller, wherein said vertical adjustor means further includesa deflection element disposed in said cavity and coupled to said supportmember, said second cable operationally coupled to said deflectionelement such that said deflection element deflects said second cablebetween said second controller and lordosis support.
 32. A back rest fora seat, said back rest comprising:a support member defining an opening;a separately formed bulge member having side surfaces and a centralplate recessed from and integral with said side surfaces to define acavity, each side surface including a flange extending, outwardly fromsaid side surface and away from said central plate; connecting means forcoupling said bulge member to said support member; and a lordosissupport and a plurality of protrusions extending from said central plateand into said cavity, said lordosis support including first and secondends coupled to said plurality of protrusions, at least one of saidfirst and second lordosis support ends being coupled to said pluralityof protrusions for movement relative to said support member, saidlordosis support adapted to bow upon displacement of one of said firstend and said second end thereof toward one another thereby forming acurvature.
 33. The back rest of claim 32 further including archingadjustor means coupled to said lordosis support for adjusting thecurvature of said lordosis support, said arching adjustor means includesa first cable and a first controller, said first cable coupled to saidfirst controller, extending into said cavity, and coupled to saidlordosis support.
 34. The back rest of claim 33 wherein said archingadjustor means further includes a deflection element disposed in saidcavity and coupled to said support member, said first cableoperationally coupled to said deflection element such that saiddeflection element deflects said first cable between said firstcontroller and said lordosis support.
 35. The back rest of claim 33wherein one of said side surfaces defines an opening and said firstcable extends from said first controller, through said opening, and intosaid cavity.
 36. The back rest of claim 32 wherein each of said first,and second ends of said lordosis support are coupled to said pluralityof protrusions for movement relative to said support member.
 37. Theback rest of claim 36 further including vertical adjustor means coupledto said lordosis support for vertically moving said first and secondlordosis support ends relative to said support member, said verticaladjustor means includes a second cable and a second controller coupledto said support member for movement relative thereto, said second cablecoupled to said second controller, extending into said cavity, andcoupled to said lordosis support.
 38. The back rest of claim 37 whereinone of said side surfaces defines a hole and said second cable-extendsfrom said second controller, through said hole and into said cavity. 39.The back rest of claim 37 wherein each of said plurality of protrusionsguide the vertical movement of said lordosis support relative to saidsupport member.
 40. The back rest of claim 37 wherein said verticaladjustor means further includes a deflection element disposed in saidcavity and coupled to said support member, said second cableoperationally coupled to said deflection element such that saiddeflection element deflects said second cable between said secondcontroller and said lordosis support.
 41. The back rest of claim 32wherein said protrusions are integral with said central plate.
 42. Theback rest of claim 32 wherein at least one of said plurality ofprotrusions guide the movement of one of the first and second ends ofsaid lordosis support.
 43. The back rest of claim 32 wherein one of saidfirst and second ends of said lordosis support is fixedly coupled to atleast one of said plurality of protrusions.
 44. The back rest of claim32 wherein at least one of said plurality of protrusions is a rail andsaid lordosis support is coupled to said support member by slidingengagement with said rail.
 45. The back rest of claim 32 wherein saidcentral plate includes recesses defining said protrusions and whereinsaid lordosis support is coupled to said support member in a snap-fitengagement with said recesses.
 46. A back rest for a seat, said backrest comprising:a frame; a support member defining an opening; aseparately formed bulge member having side surfaces and a central platerecessed from and integral with said side surfaces to define a cavity,each side surface including a flange extending outwardly from said sidesurface and away from said central plate; connecting means for couplingsaid bulge member to said support member; and a connector elementcoupled to said frame and a fastening element coupled to said supportmember, said fastening element adapted to received said connectorelement in a snap-fit engagement to connect said support member to saidframe.
 47. The back rest of claim 46 wherein said connecting meansincluding first and second apertures formed in said flanges, third andfourth apertures formed in said support member to cooperate with saidfirst and second apertures, a first fastener disposable within saidfirst and third aperture to couple said bulge member to said supportmember, and a second fastener disposable within said second and fourthapertures for coupling said bulge member to said support member.
 48. Theback rest of claim 46 wherein said connecting means includes first andsecond apertures formed in said flanges of said bulge member, first andsecond extensions integral with said support member and disposablewithin said first and second apertures to couple said bulge member tosaid support member.
 49. The back rest of claim 48 wherein said firstand second extensions each include an expandable head for coupling saidbulge member to said support member.
 50. The backrest of claim 46wherein said support member is essentially rigid.